vmpooler-provider-vsphere/lib/vmpooler/providers/vsphere.rb

# frozen_string_literal: true

require 'bigdecimal'
require 'bigdecimal/util'
require 'rbvmomi'
require 'vmpooler/providers/base'

module Vmpooler
  class PoolManager
    class Provider
      class VSphere < Vmpooler::PoolManager::Provider::Base
        # The connection_pool method is normally used only for testing
        attr_reader :connection_pool

        def initialize(config, logger, metrics, redis_connection_pool, name, options)
          super(config, logger, metrics, redis_connection_pool, name, options)

          task_limit = global_config[:config].nil? || global_config[:config]['task_limit'].nil? ? 10 : global_config[:config]['task_limit'].to_i
          # The default connection pool size is:
          # Whatever is biggest from:
          #   - How many pools this provider services
          #   - Maximum number of cloning tasks allowed
          #   - Need at least 2 connections so that a pool can have inventory functions performed while cloning etc.
          default_connpool_size = [provided_pools.count, task_limit, 2].max
          connpool_size = provider_config['connection_pool_size'].nil? ? default_connpool_size : provider_config['connection_pool_size'].to_i
          # The default connection pool timeout should be quite large - 60 seconds
          connpool_timeout = provider_config['connection_pool_timeout'].nil? ? 60 : provider_config['connection_pool_timeout'].to_i
          logger.log('d', "[#{name}] ConnPool - Creating a connection pool of size #{connpool_size} with timeout #{connpool_timeout}")
          @connection_pool = Vmpooler::PoolManager::GenericConnectionPool.new(
            metrics: metrics,
            connpool_type: 'provider_connection_pool',
            connpool_provider: name,
            size: connpool_size,
            timeout: connpool_timeout
          ) do
            logger.log('d', "[#{name}] Connection Pool - Creating a connection object")
            # Need to wrap the vSphere connection object in another object. The generic connection pooler will preserve
            # the object reference for the connection, which means it cannot "reconnect" by creating an entirely new connection
            # object.  Instead by wrapping it in a Hash, the Hash object reference itself never changes but the content of the
            # Hash can change, and is preserved across invocations.
            new_conn = connect_to_vsphere
            { connection: new_conn }
          end
          @provider_hosts = {}
          @provider_hosts_lock = Mutex.new
          @redis = redis_connection_pool
        end

        # name of the provider class
        def name
          'vsphere'
        end

        def domain(pool_name)
          dns_plugin_name = pool_config(pool_name)['dns_plugin']
          dns_config(dns_plugin_name)
        end

        def folder_configured?(folder_title, base_folder, configured_folders, allowlist)
          return true if allowlist&.include?(folder_title)
          return false unless configured_folders.keys.include?(folder_title)
          return false unless configured_folders[folder_title] == base_folder

          true
        end

        def destroy_vm_and_log(vm_name, vm_object, pool, data_ttl)
          try = 0 if try.nil?
          max_tries = 3
          @redis.with_metrics do |redis|
            redis.multi do |transaction|
              transaction.srem("vmpooler__completed__#{pool}", vm_name)
              transaction.hdel("vmpooler__active__#{pool}", vm_name)
              transaction.hset("vmpooler__vm__#{vm_name}", 'destroy', Time.now.to_s)

              # Auto-expire metadata key
              transaction.expire("vmpooler__vm__#{vm_name}", (data_ttl * 60 * 60))
            end
          end

          start = Time.now

          if vm_object.is_a? RbVmomi::VIM::Folder
            logger.log('s', "[!] [#{pool}] '#{vm_name}' is a folder, bailing on destroying")
            raise('Expected VM, but received a folder object')
          end
          vm_object.PowerOffVM_Task.wait_for_completion if vm_object.runtime&.powerState && vm_object.runtime.powerState == 'poweredOn'
          vm_object.Destroy_Task.wait_for_completion

          finish = format('%<time>.2f', time: Time.now - start)
          logger.log('s', "[-] [#{pool}] '#{vm_name}' destroyed in #{finish} seconds")
          metrics.timing("destroy.#{pool}", finish)
        rescue RuntimeError
          raise
        rescue StandardError => e
          try += 1
          logger.log('s', "[!] [#{pool}] failed to destroy '#{vm_name}' with an error: #{e}")
          try >= max_tries ? raise : retry
        end

        def destroy_folder_and_children(folder_object)
          vms = {}
          data_ttl = $config[:redis]['data_ttl'].to_i
          folder_name = folder_object.name
          unless folder_object.childEntity.count == 0
            folder_object.childEntity.each do |vm|
              vms[vm.name] = vm
            end

            vms.each do |vm_name, vm_object|
              destroy_vm_and_log(vm_name, vm_object, folder_name, data_ttl)
            end
          end
          destroy_folder(folder_object)
        end

        def destroy_folder(folder_object)
          try = 0 if try.nil?
          max_tries = 3
          logger.log('s', "[-] [#{folder_object.name}] removing unconfigured folder")
          folder_object.Destroy_Task.wait_for_completion
        rescue StandardError
          try += 1
          try >= max_tries ? raise : retry
        end

        # Return a list of pool folders
        def pool_folders(provider_name)
          folders = {}
          $config[:pools].each do |pool|
            next unless pool['provider'] == provider_name.to_s

            folder_parts = pool['folder'].split('/')
            datacenter = get_target_datacenter_from_config(pool['name'])
            folders[folder_parts.pop] = "#{datacenter}/vm/#{folder_parts.join('/')}"
          end
          folders
        end

        def get_base_folders(folders)
          base = []
          folders.each do |_key, value|
            base << value
          end
          base.uniq
        end

        def purge_unconfigured_resources(allowlist)
          configured_folders = pool_folders(name)
          base_folders = get_base_folders(configured_folders)
          @connection_pool.with_metrics do |pool_object|
            connection = ensured_vsphere_connection(pool_object)

            base_folders.each do |base_folder|
              folder_children = get_folder_children(base_folder, connection)
              next if folder_children.empty?

              folder_children.each do |folder_hash|
                folder_hash.each do |folder_title, folder_object|
                  destroy_folder_and_children(folder_object) unless folder_configured?(folder_title, base_folder, configured_folders, allowlist)
                end
              end
            end
          end
        end

        def get_folder_children(folder_name, connection)
          folders = []

          propSpecs = { # rubocop:disable Naming/VariableName
            entity: self,
            inventoryPath: folder_name
          }
          folder_object = connection.searchIndex.FindByInventoryPath(propSpecs) # rubocop:disable Naming/VariableName

          return folders if folder_object.nil?

          folder_object.childEntity.each do |folder|
            next unless folder.is_a? RbVmomi::VIM::Folder

            folders << { folder.name => folder }
          end

          folders
        end

        def vms_in_pool(pool_name)
          vms = []
          @connection_pool.with_metrics do |pool_object|
            connection = ensured_vsphere_connection(pool_object)
            folder_object = find_vm_folder(pool_name, connection)

            return vms if folder_object.nil?

            folder_object.childEntity.each do |vm|
              vms << { 'name' => vm.name } if vm.is_a? RbVmomi::VIM::VirtualMachine
            end
          end
          vms
        end

        def select_target_hosts(target, cluster, datacenter)
          percentage = 100
          dc = "#{datacenter}_#{cluster}"
          @provider_hosts_lock.synchronize do
            begin
              target[dc] = {} unless target.key?(dc)
              target[dc]['checking'] = true
              hosts_hash = find_least_used_hosts(cluster, datacenter, percentage)
              target[dc] = hosts_hash
            rescue StandardError
              target[dc] = {}
              raise
            ensure
              target[dc]['check_time_finished'] = Time.now
            end
          end
        end

        def run_select_hosts(pool_name, target)
          now = Time.now
          max_age = @config[:config]['host_selection_max_age'] || 60
          loop_delay = 5
          datacenter = get_target_datacenter_from_config(pool_name)
          cluster = get_target_cluster_from_config(pool_name)
          raise("cluster for pool #{pool_name} cannot be identified") if cluster.nil?
          raise("datacenter for pool #{pool_name} cannot be identified") if datacenter.nil?

          dc = "#{datacenter}_#{cluster}"
          unless target.key?(dc)
            select_target_hosts(target, cluster, datacenter)
            return
          end
          wait_for_host_selection(dc, target, loop_delay, max_age) if target[dc].key?('checking')
          select_target_hosts(target, cluster, datacenter) if target[dc].key?('check_time_finished') && now - target[dc]['check_time_finished'] > max_age
        end

        def wait_for_host_selection(dc, target, maxloop = 0, loop_delay = 1, max_age = 60)
          loop_count = 1
          until target.key?(dc) && target[dc].key?('check_time_finished')
            sleep(loop_delay)
            unless maxloop == 0
              break if loop_count >= maxloop

              loop_count += 1
            end
          end
          return unless target[dc].key?('check_time_finished')

          loop_count = 1
          while Time.now - target[dc]['check_time_finished'] > max_age
            sleep(loop_delay)
            unless maxloop == 0
              break if loop_count >= maxloop

              loop_count += 1
            end
          end
        end

        def select_next_host(pool_name, target, architecture = nil)
          datacenter = get_target_datacenter_from_config(pool_name)
          cluster = get_target_cluster_from_config(pool_name)
          raise("cluster for pool #{pool_name} cannot be identified") if cluster.nil?
          raise("datacenter for pool #{pool_name} cannot be identified") if datacenter.nil?

          dc = "#{datacenter}_#{cluster}"
          @provider_hosts_lock.synchronize do
            if architecture
              raise("there is no candidate in vcenter that meets all the required conditions, that the cluster has available hosts in a 'green' status, not in maintenance mode and not overloaded CPU and memory") unless target[dc].key?('architectures')

              host = target[dc]['architectures'][architecture].shift
              target[dc]['architectures'][architecture] << host
              if target[dc]['hosts'].include?(host)
                target[dc]['hosts'].delete(host)
                target[dc]['hosts'] << host
              end
            else
              raise("there is no candidate in vcenter that meets all the required conditions, that the cluster has available hosts in a 'green' status, not in maintenance mode and not overloaded CPU and memory") unless target[dc].key?('hosts')

              host = target[dc]['hosts'].shift
              target[dc]['hosts'] << host
              target[dc]['architectures'].each do |arch|
                target[dc]['architectures'][arch] = arch.partition { |v| v != host }.flatten if arch.include?(host)
              end
            end

            return host
          end
        end

        def vm_in_target?(pool_name, parent_host, architecture, target)
          datacenter = get_target_datacenter_from_config(pool_name)
          cluster = get_target_cluster_from_config(pool_name)
          raise("cluster for pool #{pool_name} cannot be identified") if cluster.nil?
          raise("datacenter for pool #{pool_name} cannot be identified") if datacenter.nil?

          dc = "#{datacenter}_#{cluster}"
          raise("there is no candidate in vcenter that meets all the required conditions, that the cluster has available hosts in a 'green' status, not in maintenance mode and not overloaded CPU and memory") unless target[dc].key?('hosts')
          return true if target[dc]['hosts'].include?(parent_host)
          return true if target[dc]['architectures'][architecture].include?(parent_host)

          false
        end

        def get_vm(pool_name, vm_name)
          vm_hash = nil
          @connection_pool.with_metrics do |pool_object|
            connection = ensured_vsphere_connection(pool_object)
            vm_object = find_vm(pool_name, vm_name, connection)
            return vm_hash if vm_object.nil?

            vm_hash = generate_vm_hash(vm_object, pool_name)
          end
          vm_hash
        end

        def create_vm(pool_name, new_vmname)
          pool = pool_config(pool_name)
          raise("Pool #{pool_name} does not exist for the provider #{name}") if pool.nil?

          vm_hash = nil
          @connection_pool.with_metrics do |pool_object|
            connection = ensured_vsphere_connection(pool_object)
            # Assume all pool config is valid i.e. not missing
            template_path = pool['template']
            target_folder_path = pool['folder']
            target_datastore = pool['datastore']
            target_datacenter_name = get_target_datacenter_from_config(pool_name)

            # Get the template VM object
            raise("Pool #{pool_name} did not specify a full path for the template for the provider #{name}") unless valid_template_path? template_path

            template_vm_object = find_template_vm(pool, connection)

            extra_config = [
              { key: 'guestinfo.hostname', value: new_vmname }
            ]

            if pool.key?('snapshot_mainMem_ioBlockPages')
              ioblockpages = pool['snapshot_mainMem_ioBlockPages']
              extra_config.push(
                { key: 'mainMem.ioBlockPages', value: ioblockpages }
              )
            end
            if pool.key?('snapshot_mainMem_iowait')
              iowait = pool['snapshot_mainMem_iowait']
              extra_config.push(
                { key: 'mainMem.iowait', value: iowait }
              )
            end

            # Annotate with creation time, origin template, etc.
            # Add extraconfig options that can be queried by vmtools
            config_spec = create_config_spec(new_vmname, template_path, extra_config)

            # Check if alternate network configuration is specified and add configuration
            if pool.key?('network')
              template_vm_network_device = template_vm_object.config.hardware.device.grep(RbVmomi::VIM::VirtualEthernetCard).first
              network_name = pool['network']
              network_device = set_network_device(target_datacenter_name, template_vm_network_device, network_name, connection)
              config_spec.deviceChange = [{ operation: 'edit', device: network_device }]
            end

            # Put the VM in the specified folder and resource pool
            relocate_spec = create_relocate_spec(target_datastore, target_datacenter_name, pool_name, connection)

            # Create a clone spec
            clone_spec = create_clone_spec(relocate_spec, config_spec)

            begin
              vm_target_folder = find_vm_folder(pool_name, connection)
              vm_target_folder ||= create_folder(connection, target_folder_path, target_datacenter_name) if @config[:config].key?('create_folders') && (@config[:config]['create_folders'] == true)
            rescue StandardError
              if @config[:config].key?('create_folders') && (@config[:config]['create_folders'] == true)
                vm_target_folder = create_folder(connection, target_folder_path, target_datacenter_name)
              else
                raise
              end
            end
            raise ArgumentError, "Cannot find the configured folder for #{pool_name} #{target_folder_path}" unless vm_target_folder

            # Create the new VM
            new_vm_object = template_vm_object.CloneVM_Task(
              folder: vm_target_folder,
              name: new_vmname,
              spec: clone_spec
            ).wait_for_completion

            vm_hash = generate_vm_hash(new_vm_object, pool_name)
          end
          vm_hash
        end

        # The inner method requires vmware tools running in the guest os
        def get_vm_ip_address(vm_name, pool_name)
          @connection_pool.with_metrics do |pool_object|
            connection = ensured_vsphere_connection(pool_object)
            vm_object = find_vm(pool_name, vm_name, connection)
            vm_hash = generate_vm_hash(vm_object, pool_name)
            return vm_hash['ip']
          end
        end

        def create_config_spec(vm_name, template_name, extra_config)
          RbVmomi::VIM.VirtualMachineConfigSpec(
            annotation: JSON.pretty_generate(
              name: vm_name,
              created_by: provider_config['username'],
              base_template: template_name,
              creation_timestamp: Time.now.utc
            ),
            extraConfig: extra_config
          )
        end

        def create_relocate_spec(target_datastore, target_datacenter_name, pool_name, connection)
          pool = pool_config(pool_name)
          target_cluster_name = get_target_cluster_from_config(pool_name)

          relocate_spec = RbVmomi::VIM.VirtualMachineRelocateSpec(
            datastore: find_datastore(target_datastore, connection, target_datacenter_name),
            diskMoveType: get_disk_backing(pool)
          )
          manage_host_selection = @config[:config]['manage_host_selection'] if @config[:config].key?('manage_host_selection')
          if manage_host_selection
            run_select_hosts(pool_name, @provider_hosts)
            target_host = select_next_host(pool_name, @provider_hosts)
            host_object = find_host_by_dnsname(connection, target_host)
            relocate_spec.host = host_object
          else
            # Choose a cluster/host to place the new VM on
            target_cluster_object = find_cluster(target_cluster_name, connection, target_datacenter_name)
            relocate_spec.pool = target_cluster_object.resourcePool
          end
          relocate_spec
        end

        def create_clone_spec(relocate_spec, config_spec)
          RbVmomi::VIM.VirtualMachineCloneSpec(
            location: relocate_spec,
            config: config_spec,
            powerOn: true,
            template: false
          )
        end

        def set_network_device(datacenter_name, template_vm_network_device, network_name, connection)
          # Retrieve network object
          datacenter = connection.serviceInstance.find_datacenter(datacenter_name)
          new_network = datacenter.network.find { |n| n.name == network_name }

          raise("Cannot find network #{network_name} in datacenter #{datacenter_name}") unless new_network

          # Determine network device type
          # All possible device type options here: https://vdc-download.vmware.com/vmwb-repository/dcr-public/98d63b35-d822-47fe-a87a-ddefd469df06/2e3c7b58-f2bd-486e-8bb1-a75eb0640bee/doc/vim.vm.device.VirtualEthernetCard.html
          network_device =
            if template_vm_network_device.instance_of? RbVmomi::VIM::VirtualVmxnet2
              RbVmomi::VIM.VirtualVmxnet2
            elsif template_vm_network_device.instance_of? RbVmomi::VIM::VirtualVmxnet3
              RbVmomi::VIM.VirtualVmxnet3
            elsif template_vm_network_device.instance_of? RbVmomi::VIM::VirtualE1000
              RbVmomi::VIM.VirtualE1000
            elsif template_vm_network_device.instance_of? RbVmomi::VIM::VirtualE1000e
              RbVmomi::VIM.VirtualE1000e
            elsif template_vm_network_device.instance_of? RbVmomi::VIM::VirtualSriovEthernetCard
              RbVmomi::VIM.VirtualSriovEthernetCard
            else
              RbVmomi::VIM.VirtualPCNet32
            end

          # Set up new network device attributes
          network_device.key = template_vm_network_device.key
          network_device.deviceInfo = RbVmomi::VIM.Description(
            label: template_vm_network_device.deviceInfo.label,
            summary: network_name
          )
          network_device.backing = RbVmomi::VIM.VirtualEthernetCardNetworkBackingInfo(
            deviceName: network_name,
            network: new_network,
            useAutoDetect: false
          )
          network_device.addressType = 'assigned'
          network_device.connectable = RbVmomi::VIM.VirtualDeviceConnectInfo(
            allowGuestControl: true,
            startConnected: true,
            connected: true
          )
          network_device
        end

        def create_disk(pool_name, vm_name, disk_size)
          pool = pool_config(pool_name)
          raise("Pool #{pool_name} does not exist for the provider #{name}") if pool.nil?

          datastore_name = pool['datastore']
          raise("Pool #{pool_name} does not have a datastore defined for the provider #{name}") if datastore_name.nil?

          @connection_pool.with_metrics do |pool_object|
            connection = ensured_vsphere_connection(pool_object)
            vm_object = find_vm(pool_name, vm_name, connection)
            raise("VM #{vm_name} in pool #{pool_name} does not exist for the provider #{name}") if vm_object.nil?

            add_disk(vm_object, disk_size, datastore_name, connection, get_target_datacenter_from_config(pool_name))
          end
          true
        end

        def create_snapshot(pool_name, vm_name, new_snapshot_name)
          @connection_pool.with_metrics do |pool_object|
            connection = ensured_vsphere_connection(pool_object)
            vm_object = find_vm(pool_name, vm_name, connection)
            raise("VM #{vm_name} in pool #{pool_name} does not exist for the provider #{name}") if vm_object.nil?

            old_snap = find_snapshot(vm_object, new_snapshot_name)
            raise("Snapshot #{new_snapshot_name} for VM #{vm_name} in pool #{pool_name} already exists for the provider #{name}") unless old_snap.nil?

            vm_object.CreateSnapshot_Task(
              name: new_snapshot_name,
              description: 'vmpooler',
              memory: true,
              quiesce: true
            ).wait_for_completion
          end
          true
        end

        def revert_snapshot(pool_name, vm_name, snapshot_name)
          @connection_pool.with_metrics do |pool_object|
            connection = ensured_vsphere_connection(pool_object)
            vm_object = find_vm(pool_name, vm_name, connection)
            raise("VM #{vm_name} in pool #{pool_name} does not exist for the provider #{name}") if vm_object.nil?

            snapshot_object = find_snapshot(vm_object, snapshot_name)
            raise("Snapshot #{snapshot_name} for VM #{vm_name} in pool #{pool_name} does not exist for the provider #{name}") if snapshot_object.nil?

            snapshot_object.RevertToSnapshot_Task.wait_for_completion
          end
          true
        end

        def destroy_vm(pool_name, vm_name)
          @connection_pool.with_metrics do |pool_object|
            connection = ensured_vsphere_connection(pool_object)
            vm_object = find_vm(pool_name, vm_name, connection)
            # If a VM doesn't exist then it is effectively deleted
            return true if vm_object.nil?

            # Poweroff the VM if it's running
            vm_object.PowerOffVM_Task.wait_for_completion if vm_object.runtime&.powerState && vm_object.runtime.powerState == 'poweredOn'

            # Kill it with fire
            vm_object.Destroy_Task.wait_for_completion
          end
          true
        end

        def vm_ready?(pool_name, vm_name, redis)
          begin
            domain = domain(pool_name)
            open_socket(vm_name, domain)
          rescue StandardError => e
            redis.hset("vmpooler__vm__#{vm_name}", 'open_socket_error', e.to_s)
            return false
          end
          redis.hdel("vmpooler__vm__#{vm_name}", 'open_socket_error')
          true
        end

        # VSphere Helper methods

        def get_target_cluster_from_config(pool_name)
          pool = pool_config(pool_name)
          return nil if pool.nil?

          return pool['clone_target'] unless pool['clone_target'].nil?
          return global_config[:config]['clone_target'] unless global_config[:config]['clone_target'].nil?

          nil
        end

        def get_target_datacenter_from_config(pool_name)
          pool = pool_config(pool_name)
          return nil if pool.nil?

          return pool['datacenter']            unless pool['datacenter'].nil?
          return provider_config['datacenter'] unless provider_config['datacenter'].nil?

          nil
        end

        # Return a hash of VM data
        # Provides vmname, hostname, template, poolname, boottime and powerstate information
        def generate_vm_hash(vm_object, pool_name)
          pool_configuration = pool_config(pool_name)
          return nil if pool_configuration.nil?

          hostname = vm_object.summary.guest.hostName if vm_object.summary&.guest && vm_object.summary.guest.hostName
          boottime = vm_object.runtime.bootTime if vm_object.runtime&.bootTime
          powerstate = vm_object.runtime.powerState if vm_object.runtime&.powerState

          ip_maxloop = 240
          ip_loop_delay = 1
          ip_loop_count = 1
          ip = nil
          invalid_addresses = /(0|169)\.(0|254)\.\d+\.\d+/
          while ip.nil?
            sleep(ip_loop_delay)
            ip = vm_object.guest_ip
            ip = nil if !ip.nil? && ip.match?(invalid_addresses)
            unless ip_maxloop == 0
              break if ip_loop_count >= ip_maxloop

              ip_loop_count += 1
            end
          end

          {
            'name' => vm_object.name,
            'hostname' => hostname,
            'template' => pool_configuration['template'],
            'poolname' => pool_name,
            'boottime' => boottime,
            'powerstate' => powerstate,
            'ip' => ip
          }
        end

        # vSphere helper methods
        ADAPTER_TYPE = 'lsiLogic'
        DISK_TYPE = 'thin'
        DISK_MODE = 'persistent'

        def ensured_vsphere_connection(connection_pool_object)
          connection_pool_object[:connection] = connect_to_vsphere unless vsphere_connection_ok?(connection_pool_object[:connection])
          connection_pool_object[:connection]
        end

        def vsphere_connection_ok?(connection)
          _result = connection.serviceInstance.CurrentTime
          true
        rescue StandardError
          false
        end

        def connect_to_vsphere
          max_tries = global_config[:config]['max_tries'] || 3
          retry_factor = global_config[:config]['retry_factor'] || 10
          try = 1
          begin
            connection = RbVmomi::VIM.connect host: provider_config['server'],
                                              user: provider_config['username'],
                                              password: provider_config['password'],
                                              insecure: provider_config['insecure'] || false
            metrics.increment('connect.open')
            connection
          rescue StandardError => e
            metrics.increment('connect.fail')
            raise e if try >= max_tries

            sleep(try * retry_factor)
            try += 1
            retry
          end
        end

        # This should supercede the open_socket method in the Pool Manager
        def open_socket(host, domain = nil, timeout = 5, port = 22, &_block)
          target_host = host
          target_host = "#{host}.#{domain}" if domain
          sock = TCPSocket.new(target_host, port, connect_timeout: timeout)
          begin
            yield sock if block_given?
          ensure
            sock.close
          end
        end

        def get_vm_folder_path(vm_object)
          # This gives an array starting from the root Datacenters folder all the way to the VM
          # [ [Object, String], [Object, String ] ... ]
          # It's then reversed so that it now goes from the VM to the Datacenter
          full_path = vm_object.path.reverse

          # Find the Datacenter object
          dc_index = full_path.index { |p| p[0].is_a?(RbVmomi::VIM::Datacenter) }
          return nil if dc_index.nil?
          # The Datacenter should be at least 2 otherwise there's something
          # wrong with the array passed in
          # This is the minimum:
          # [ VM (0), VM ROOT FOLDER (1), DC (2)]
          return nil if dc_index <= 1

          # Remove the VM name (Starting position of 1 in the slice)
          # Up until the Root VM Folder of DataCenter Node (dc_index - 2)
          full_path = full_path.slice(1..dc_index - 2)

          # Reverse the array back to normal and
          # then convert the array of paths into a '/' seperated string
          (full_path.reverse.map { |p| p[1] }).join('/')
        end

        def add_disk(vm, size, datastore, connection, datacentername)
          return false unless size.to_i > 0

          vmdk_datastore = find_datastore(datastore, connection, datacentername)
          raise("Datastore '#{datastore}' does not exist in datacenter '#{datacentername}'") if vmdk_datastore.nil?

          datacenter = connection.serviceInstance.find_datacenter(datacentername)
          controller = find_disk_controller(vm)
          disk_unit_number = find_disk_unit_number(vm, controller)
          disk_count = vm.config.hardware.device.grep(RbVmomi::VIM::VirtualDisk).count
          vmdk_file_name = "#{vm['name']}/#{vm['name']}_#{disk_count}.vmdk"

          vmdk_spec = RbVmomi::VIM::FileBackedVirtualDiskSpec(
            capacityKb: size.to_i * 1024 * 1024,
            adapterType: ADAPTER_TYPE,
            diskType: DISK_TYPE
          )

          vmdk_backing = RbVmomi::VIM::VirtualDiskFlatVer2BackingInfo(
            datastore: vmdk_datastore,
            diskMode: DISK_MODE,
            fileName: "[#{datastore}] #{vmdk_file_name}"
          )

          device = RbVmomi::VIM::VirtualDisk(
            backing: vmdk_backing,
            capacityInKB: size.to_i * 1024 * 1024,
            controllerKey: controller.key,
            key: -1,
            unitNumber: disk_unit_number
          )

          device_config_spec = RbVmomi::VIM::VirtualDeviceConfigSpec(
            device: device,
            operation: RbVmomi::VIM::VirtualDeviceConfigSpecOperation('add')
          )

          vm_config_spec = RbVmomi::VIM::VirtualMachineConfigSpec(
            deviceChange: [device_config_spec]
          )

          connection.serviceContent.virtualDiskManager.CreateVirtualDisk_Task(
            datacenter: datacenter,
            name: "[#{datastore}] #{vmdk_file_name}",
            spec: vmdk_spec
          ).wait_for_completion

          vm.ReconfigVM_Task(spec: vm_config_spec).wait_for_completion

          true
        end

        def find_datastore(datastorename, connection, datacentername)
          datacenter = connection.serviceInstance.find_datacenter(datacentername)
          raise("Datacenter #{datacentername} does not exist") if datacenter.nil?

          datacenter.find_datastore(datastorename)
        end

        def find_device(vm, device_name)
          vm.config.hardware.device.each do |device|
            return device if device.deviceInfo.label == device_name
          end

          nil
        end

        def find_disk_controller(vm)
          devices = find_disk_devices(vm)

          devices.keys.sort.each do |device|
            return find_device(vm, devices[device]['device'].deviceInfo.label) if devices[device]['children'].length < 15
          end

          nil
        end

        def find_disk_devices(vm)
          devices = {}

          vm.config.hardware.device.each do |device|
            if device.is_a? RbVmomi::VIM::VirtualSCSIController
              if devices[device.controllerKey].nil?
                devices[device.key] = {}
                devices[device.key]['children'] = []
              end

              devices[device.key]['device'] = device
            end

            if device.is_a? RbVmomi::VIM::VirtualDisk
              if devices[device.controllerKey].nil?
                devices[device.controllerKey] = {}
                devices[device.controllerKey]['children'] = []
              end

              devices[device.controllerKey]['children'].push(device)
            end
          end

          devices
        end

        def find_disk_unit_number(vm, controller)
          used_unit_numbers = []
          available_unit_numbers = []

          devices = find_disk_devices(vm)

          devices.keys.sort.each do |c|
            next unless controller.key == devices[c]['device'].key

            used_unit_numbers.push(devices[c]['device'].scsiCtlrUnitNumber)
            devices[c]['children'].each do |disk|
              used_unit_numbers.push(disk.unitNumber)
            end
          end

          (0..15).each do |scsi_id|
            available_unit_numbers.push(scsi_id) if used_unit_numbers.grep(scsi_id).length <= 0
          end

          available_unit_numbers.min
        end

        # Finds a folder object by inventory path
        # Params:
        # +pool_name+:: the pool to find the folder for
        # +connection+:: the vsphere connection object
        # returns a ManagedObjectReference for the folder found or nil if not found
        def find_vm_folder(pool_name, connection)
          # Find a folder by its inventory path and return the object
          # Returns nil when the object found is not a folder
          pool_configuration = pool_config(pool_name)
          return nil if pool_configuration.nil?

          folder = pool_configuration['folder']
          datacenter = get_target_datacenter_from_config(pool_name)
          return nil if datacenter.nil?

          propSpecs = { # rubocop:disable Naming/VariableName
            entity: self,
            inventoryPath: "#{datacenter}/vm/#{folder}"
          }

          folder_object = connection.searchIndex.FindByInventoryPath(propSpecs) # rubocop:disable Naming/VariableName
          return nil unless folder_object.instance_of? RbVmomi::VIM::Folder

          folder_object
        end

        # Returns an array containing cumulative CPU and memory utilization of a host, and its object reference
        # Params:
        # +model+:: CPU arch version to match on
        # +limit+:: Hard limit for CPU or memory utilization beyond which a host is excluded for deployments
        # returns nil if one on these conditions is true:
        #    the model param is defined and cannot be found
        #    the host is in maintenance mode
        #    the host status is not 'green'
        #    the cpu or memory utilization is bigger than the limit param
        def get_host_utilization(host, model = nil, limit = 90)
          limit = @config[:config]['utilization_limit'] if @config[:config].key?('utilization_limit')
          return nil if model && !host_has_cpu_model?(host, model)
          return nil if host.runtime.inMaintenanceMode
          return nil unless host.overallStatus == 'green'
          return nil unless host.configIssue.empty?

          cpu_utilization = cpu_utilization_for host
          memory_utilization = memory_utilization_for host

          return nil if cpu_utilization.nil?
          return nil if cpu_utilization.to_d == 0.0.to_d
          return nil if memory_utilization.nil?
          return nil if memory_utilization.to_d == 0.0.to_d

          return nil if cpu_utilization > limit
          return nil if memory_utilization > limit

          [cpu_utilization, host]
        end

        def host_has_cpu_model?(host, model)
          get_host_cpu_arch_version(host) == model
        end

        def get_host_cpu_arch_version(host)
          cpu_model = host.hardware.cpuPkg[0].description
          cpu_model_parts = cpu_model.split
          cpu_model_parts[4]
        end

        def cpu_utilization_for(host)
          cpu_usage = host.summary.quickStats.overallCpuUsage
          return nil if cpu_usage.nil?

          cpu_size = host.summary.hardware.cpuMhz * host.summary.hardware.numCpuCores
          cpu_usage.fdiv(cpu_size) * 100
        end

        def memory_utilization_for(host)
          memory_usage = host.summary.quickStats.overallMemoryUsage
          return nil if memory_usage.nil?

          memory_size = host.summary.hardware.memorySize / 1024 / 1024
          memory_usage.fdiv(memory_size) * 100
        end

        def get_average_cluster_utilization(hosts)
          utilization_counts = hosts.map { |host| host[0] }
          utilization_counts.inject(:+) / hosts.count
        end

        def build_compatible_hosts_lists(hosts, percentage)
          hosts_with_arch_versions = hosts.map do |h|
            {
              'utilization' => h[0],
              'host_object' => h[1],
              'architecture' => get_host_cpu_arch_version(h[1])
            }
          end
          versions = hosts_with_arch_versions.map { |host| host['architecture'] }.uniq
          architectures = {}
          versions.each do |version|
            architectures[version] = []
          end

          hosts_with_arch_versions.each do |h|
            architectures[h['architecture']] << [h['utilization'], h['host_object'], h['architecture']]
          end

          versions.each do |version|
            targets = select_least_used_hosts(architectures[version], percentage)
            architectures[version] = targets
          end
          architectures
        end

        def select_least_used_hosts(hosts, percentage)
          raise('Provided hosts list to select_least_used_hosts is empty') if hosts.empty?

          average_utilization = get_average_cluster_utilization(hosts)
          least_used_hosts = []
          hosts.each do |host|
            least_used_hosts << host if host[0] <= average_utilization
          end
          hosts_to_select = (hosts.count * (percentage / 100.0)).to_int
          hosts_to_select = hosts.count - 1 if percentage == 100
          least_used_hosts.sort[0..hosts_to_select].map { |host| host[1].name }
        end

        def find_least_used_hosts(cluster, datacentername, percentage)
          @connection_pool.with_metrics do |pool_object|
            connection = ensured_vsphere_connection(pool_object)
            cluster_object = find_cluster(cluster, connection, datacentername)
            raise("Cluster #{cluster} cannot be found") if cluster_object.nil?

            target_hosts = get_cluster_host_utilization(cluster_object)
            raise("there is no candidate in vcenter that meets all the required conditions, that the cluster has available hosts in a 'green' status, not in maintenance mode and not overloaded CPU and memory'") if target_hosts.empty?

            architectures = build_compatible_hosts_lists(target_hosts, percentage)
            least_used_hosts = select_least_used_hosts(target_hosts, percentage)
            {
              'hosts' => least_used_hosts,
              'architectures' => architectures
            }
          end
        end

        def find_host_by_dnsname(connection, dnsname)
          host_object = connection.searchIndex.FindByDnsName(dnsName: dnsname, vmSearch: false)
          return nil if host_object.nil?

          host_object
        end

        def find_least_used_host(cluster, connection, datacentername)
          cluster_object = find_cluster(cluster, connection, datacentername)
          target_hosts = get_cluster_host_utilization(cluster_object)
          raise("There is no host candidate in vcenter that meets all the required conditions, check that the cluster has available hosts in a 'green' status, not in maintenance mode and not overloaded CPU and memory'") if target_hosts.empty?

          target_hosts.min[1]
        end

        def find_cluster(cluster, connection, datacentername)
          datacenter = connection.serviceInstance.find_datacenter(datacentername)
          raise("Datacenter #{datacentername} does not exist") if datacenter.nil?

          # In the event the cluster is not a direct descendent of the
          # datacenter, we use a ContainerView to leverage its recursive
          # search. This will find clusters which are, for example, in
          # folders under the datacenter. This will also find standalone
          # hosts which are not part of a cluster.
          cv = connection.serviceContent.viewManager.CreateContainerView(
            container: datacenter.hostFolder,
            type: ['ComputeResource', 'ClusterComputeResource'],
            recursive: true
          )
          cluster = cv.view.find { |cluster_object| cluster_object.name == cluster }
          cv.DestroyView
          cluster
        end

        def get_cluster_host_utilization(cluster, model = nil)
          cluster_hosts = []
          cluster.host.each do |host|
            host_usage = get_host_utilization(host, model)
            cluster_hosts << host_usage if host_usage
          end
          cluster_hosts
        end

        def find_least_used_vpshere_compatible_host(vm)
          source_host = vm.summary.runtime.host
          model = get_host_cpu_arch_version(source_host)
          cluster = source_host.parent
          target_hosts = get_cluster_host_utilization(cluster, model)
          raise("There is no host candidate in vcenter that meets all the required conditions, check that the cluster has available hosts in a 'green' status, not in maintenance mode and not overloaded CPU and memory'") if target_hosts.empty?

          target_host = target_hosts.min[1]
          [target_host, target_host.name]
        end

        def find_snapshot(vm, snapshotname)
          get_snapshot_list(vm.snapshot.rootSnapshotList, snapshotname) if vm.snapshot
        end

        def build_propSpecs(datacenter, folder, vmname) # rubocop:disable Naming/MethodName
          {
            entity => self,
            :inventoryPath => "#{datacenter}/vm/#{folder}/#{vmname}"
          }
        end

        def find_vm(pool_name, vmname, connection)
          # Find a VM by its inventory path and return the VM object
          # Returns nil when a VM, or pool configuration, cannot be found
          pool_configuration = pool_config(pool_name)
          return nil if pool_configuration.nil?

          folder = pool_configuration['folder']
          datacenter = get_target_datacenter_from_config(pool_name)
          return nil if datacenter.nil?

          propSpecs = { # rubocop:disable Naming/VariableName
            entity: self,
            inventoryPath: "#{datacenter}/vm/#{folder}/#{vmname}"
          }

          connection.searchIndex.FindByInventoryPath(propSpecs) # rubocop:disable Naming/VariableName
        end

        def get_base_vm_container_from(connection)
          view_manager = connection.serviceContent.viewManager
          view_manager.CreateContainerView(
            container: connection.serviceContent.rootFolder,
            recursive: true,
            type: ['VirtualMachine']
          )
        end

        def get_snapshot_list(tree, snapshotname)
          snapshot = nil

          tree.each do |child|
            if child.name == snapshotname
              snapshot ||= child.snapshot
            else
              snapshot ||= get_snapshot_list(child.childSnapshotList, snapshotname)
            end
          end

          snapshot
        end

        def get_vm_details(pool_name, vm_name, connection)
          vm_object = find_vm(pool_name, vm_name, connection)
          return nil if vm_object.nil?

          parent_host_object = vm_object.summary.runtime.host if vm_object.summary&.runtime && vm_object.summary.runtime.host
          raise('Unable to determine which host the VM is running on') if parent_host_object.nil?

          parent_host = parent_host_object.name
          architecture = get_host_cpu_arch_version(parent_host_object)
          {
            'host_name' => parent_host,
            'object' => vm_object,
            'architecture' => architecture
          }
        end

        def migration_enabled?(config)
          migration_limit = config[:config]['migration_limit']
          return false unless migration_limit.is_a? Integer
          return true if migration_limit > 0

          false
        end

        def migrate_vm(pool_name, vm_name)
          @connection_pool.with_metrics do |pool_object|
            begin
              connection = ensured_vsphere_connection(pool_object)
              vm_hash = get_vm_details(pool_name, vm_name, connection)
              @redis.with_metrics do |redis|
                redis.hset("vmpooler__vm__#{vm_name}", 'host', vm_hash['host_name'])
                migration_count = redis.scard('vmpooler__migration')
                migration_limit = @config[:config]['migration_limit'] if @config[:config].key?('migration_limit')
                if migration_enabled? @config
                  if migration_count >= migration_limit
                    logger.log('s', "[ ] [#{pool_name}] '#{vm_name}' is running on #{vm_hash['host_name']}. No migration will be evaluated since the migration_limit has been reached")
                    break
                  end
                  run_select_hosts(pool_name, @provider_hosts)
                  migrate_vm_to_new_host(pool_name, vm_name, vm_hash, connection)
                  
                else
                  logger.log('s', "[ ] [#{pool_name}] '#{vm_name}' is running on #{vm_hash['host_name']}")
                end
              end
            rescue StandardError
              logger.log('s', "[!] [#{pool_name}] '#{vm_name}' is running on #{vm_hash['host_name']}")
              raise
            end
          end
        end

        def migrate_vm_to_new_host(pool_name, vm_name, vm_hash, connection)
          @redis.with_metrics do |redis|
            redis.sadd('vmpooler__migration', vm_name)
          end
          target_host_name = select_next_host(pool_name, @provider_hosts, vm_hash['architecture'])
          target_host_object = find_host_by_dnsname(connection, target_host_name)
          finish = migrate_vm_and_record_timing(pool_name, vm_name, vm_hash, target_host_object, target_host_name)
          @redis.with_metrics do |redis|
            redis.multi do |transaction|
              transaction.hset("vmpooler__vm__#{vm_name}", 'host', target_host_name)
              transaction.hset("vmpooler__vm__#{vm_name}", 'migrated', 'true')
            end
          end
          logger.log('s', "[>] [#{pool_name}] '#{vm_name}' migrated from #{vm_hash['host_name']} to #{target_host_name} in #{finish} seconds")
        ensure
          @redis.with_metrics do |redis|
            redis.srem('vmpooler__migration', vm_name)
          end
        end

        def migrate_vm_and_record_timing(pool_name, vm_name, vm_hash, target_host_object, dest_host_name)
          start = Time.now
          migrate_vm_host(vm_hash['object'], target_host_object)
          finish = format('%<time>.2f', time: Time.now - start)
          metrics.timing("migrate.#{pool_name}", finish)
          metrics.increment("migrate_from.#{vm_hash['host_name']}")
          metrics.increment("migrate_to.#{dest_host_name}")
          @redis.with_metrics do |redis|
            checkout_to_migration = format('%<time>.2f', time: Time.now - Time.parse(redis.hget("vmpooler__vm__#{vm_name}", 'checkout')))
            redis.multi do |transaction|
              transaction.hset("vmpooler__vm__#{vm_name}", 'migration_time', finish)
              transaction.hset("vmpooler__vm__#{vm_name}", 'checkout_to_migration', checkout_to_migration)
            end
          end
          finish
        end

        def migrate_vm_host(vm_object, host)
          relospec = RbVmomi::VIM.VirtualMachineRelocateSpec(host: host)
          vm_object.RelocateVM_Task(spec: relospec).wait_for_completion
        end

        def create_folder(connection, new_folder, datacenter)
          dc = connection.serviceInstance.find_datacenter(datacenter)
          folder_object = dc.vmFolder.traverse(new_folder, RbVmomi::VIM::Folder, true)
          raise("Cannot create folder #{new_folder}") if folder_object.nil?

          folder_object
        end

        def find_template_vm(pool, connection)
          datacenter = get_target_datacenter_from_config(pool['name'])
          raise('cannot find datacenter') if datacenter.nil?

          propSpecs = { # rubocop:disable Naming/VariableName
            entity: self,
            inventoryPath: "#{datacenter}/vm/#{pool['template']}"
          }

          template_vm_object = connection.searchIndex.FindByInventoryPath(propSpecs) # rubocop:disable Naming/VariableName
          raise("Pool #{pool['name']} specifies a template VM of #{pool['template']} which does not exist for the provider #{name}") if template_vm_object.nil?

          template_vm_object
        end

        def create_template_delta_disks(pool)
          @connection_pool.with_metrics do |pool_object|
            connection = ensured_vsphere_connection(pool_object)
            template_vm_object = find_template_vm(pool, connection)

            template_vm_object.add_delta_disk_layer_on_all_disks
          end
        end

        def valid_template_path?(template)
          return false unless template.include?('/')
          return false if template[0] == '/'
          return false if template[-1] == '/'

          true
        end

        def get_disk_backing(pool)
          return :moveChildMostDiskBacking if linked_clone?(pool)

          :moveAllDiskBackingsAndConsolidate
        end

        def linked_clone?(pool)
          return if pool['create_linked_clone'] == false
          return true if pool['create_linked_clone']
          return true if @config[:config]['create_linked_clones']
        end
      end
    end
  end
end